ArticleIn this article, architect and construction expert, Bruce Corke, AIA provides an introduction to BIM and discusses how this relatively new technology is likely to affect the landscape of construction litigation in years to come.
Construction Disputes and BIM: A Primer
During much of modern history architectural designs were communicated through the medium of two dimensional hand drawings and written specifications. These technical drawings were produced by applying ink or pencil to a medium of paper, velum or Mylar. The 1990’s brought the advent of computer-aided design (CAD) as the popular medium to draw a building. In the 2000’s Building Information Models (BIM) were introduced to the architecture and engineering professions as the latest medium for designing and drawing a building. In spite of the evolution of technology over the years, construction disputes continue to occur.
A Definition of BIM
BIM is a virtual construction model of a building with the three primary spatial dimensions being width, height and depth. BIM can augment the three primary spatial dimensions with time as the fourth dimension (4D) and cost as the fifth dimension (5D). BIM therefore covers more than just geometry. It also covers spatial relationships, light analysis, geographic information, quantities and the properties of the building components. BIM allows the extraction of different views from a computerized building model for drawing production as well as other uses. BIM has the potential to be linked with construction scheduling software (4D). BIM models can also carry attributes for selecting and ordering materials automatically, providing cost estimates as well as material tracking and ordering (5D).
Potential BIM Benefits
Architects utilize BIM to create three dimensional spaces and buildings. BIM has the potential to enhance the design team’s visualization of a project as well as improve the design team’s coordination of a project. It has been shown that BIM has the ability to aid the contractor’s efforts to manage acceleration, avoid delays and mitigate disruptions.
Better coordinated 2D drawings can potentially now be extracted from BIM models. Changes to three dimensional models during the design process are automatically updated in extracted 2D drawings. Historically, 2D drawings were manually checked for coordination and accuracy. A quality control specialist spent multiple days reviewing two dimensional drawings attempting to make sure the architecture and engineering components blended properly into an integrated design. Available BIM software includes programs for semi-automated quality control. When properly utilized, these programs perform coordination checks called “clash detection”. Working in 3D, designers have the potential to identify conflicts between and amongst the building systems that might not be readily identified on 2D drawings. When properly utilized, the clash detection can eliminate serious constructability issues before work has begun onsite. This can mitigate risk by providing greater accuracy and ensuring that building systems fit in the locations shown on the drawings. Properly executed clash detection has the potential to benefit the designer, contractor and owner. It can reduce requests for information (RFIs) and change orders thereby helping to keep the project on schedule.
Renovating existing buildings and spaces always created a unique challenge for architects. Obtaining accurate existing “as-built” conditions on which to base a design was both time consuming and fraught with the potential for inaccuracies. It involved sending teams of individuals with tape measures and note pads to gather the existing building’s information from scratch. Or if existing drawings existed, the team went to verify the as-built conditions as represented on those drawings.
Point Cloud is a computerized “mapping” format that can be utilized with BIM. Point clouds of existing buildings and spaces are generated by 3D scanners. These devices optically measure a large number of points on an object’s surface, and output a “point cloud” as a data file. In a three-dimensional coordinate system, these points are defined by X, Y, and Z axis coordinates. They are intended to represent the external surface of an object, the internal surfaces of a space or sometimes a combination of both. A three dimensional BIM model can be created from these measurements. The proper utilization of 3D scanners can increase the accuracy of existing building surveys. They can thereby decrease the potential for construction site conflicts by having the proposed construction more closely integrate with the existing conditions.
BIM and the AIA
The American Institute of Architects (AIA) is the leading producer of the design and construction industry’s standardized contract documents. In 2007 the AIA explicitly stated in their Owner-Architect Agreement B101 what the standard of care was to which an architect must perform. That document, although mentioning digital models and listing BIM as an additional service, does not define BIM. In recognition that BIM was becoming a force in the industry the AIA introduced the E202 Building Information Modeling Protocol Exhibit in 2008. A key element in this protocol was the term “levels of development” or LOD, the ubiquitous five levels of progressive model element completeness. In 2013 the AIA updated this document to AIA E203 – Building Information Modeling and Digital Data Exhibit. This document expands the definition of how BIM will be utilized by the project team including: 1) who will be modeling what portions of the project including the architect, engineers and possibly the contractor; 2) what levels of LOD will be provided in the model elements; 3) if the model will be utilized for facilities management; and 4) What facilities management responsibilities the architectural firm will have and how they will be compensated for these services. It is through these documents and others that the AIA establishes a standard of care as it relates to BIM.
BIM and Design-Bid-Build vs. Design-Build
A traditional project delivery system is called design-bid-build. In this system the roles of designer, contractor and owner are clearly defined and separate. The architect and engineers design the building for the owner and create documents for use by the contractors. The contractors bid from the construction documents and ultimately build the building for the owner from them.
Another project delivery system that has become popular is design-build. Design-build relies on a contract that establishes a single point of responsibility. It is intended to minimize risks for the project owner. It is also intended to shorten the delivery schedule by overlapping the design phase and construction phase of a project. This delivery system is highly collaborative and multi-participant in nature. In the BIM platform, Architects, engineers, specialty consultants, sub-contractors, building product manufacturers and the client’s out-sourced service providers all contribute to the BIM model. Controlling each team member’s contribution to the BIM model presents challenges and must be managed properly.
BIM and Construction Disputes
Regardless of the evolution of design and drawing production, construction disputes continue to occur. BIM is a tool. All tools can be handled with varying degrees of skill.
The production of construction documents (CDs) has always required the coordination of multiple design entities. Likewise the construction of a project has always required the coordinated efforts of multiple contractors and trades. The use of point cloud enables an architect to create a 3D model of an existing building, but its accuracy is only as good as the technicians translating the data.
In the design-build delivery system responsibilities are sometimes blurred. Contractors and manufacturers are now assisting the design team with various components of the building in the BIM model. Who has the ownership and responsibility for each of the parts? What level of detail is being provided by each team member? The new AIA agreements noted above seek to help define this changing landscape of design and construction but they help only if they are properly utilized. Many future construction claims will be similar to those of the past but with the arrival of BIM and its increased capabilities there will also be new claims that arise. Contracts will need to be carefully reviewed for duties and responsibilities. BIM models and extracted 2D drawings will need to be evaluated for standard of care and workmanlike performance including model ownership and clash detection.
BIM now provides the designer with a tremendous delivery platform. Unfortunately if not properly managed; it will only result in another layer of construction disputes. The architects and engineers at Robson Forensic have consulted on a wide variety of construction disputes. Please contact us to discuss how we might assist you with yours.
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Bruce is a broadly experienced licensed architect with over 36 years of professional experience. His diverse career includes the design and construction of schools, medical buildings, multi-family residential developments, parking garages, dormitories, municipal buildings, churches, warehouses, supermarkets, libraries, laboratories and office buildings. These project types included: due diligence studies, renovations, new construction and historic preservation. Bruce’s architectural career spans every job description from designer to project manager and firm owner. He has the hands-on experience to provide technical investigations, analysis, expert reports and testimony toward the resolution of various construction disputes involving code compliance, defect claims, project delivery methods and professional liability.